Merc 7.5 - advice...

goinhungry

Seaman
Joined
Sep 8, 2005
Messages
71
Hello all. My boat's been in the shop now for much longer than I'd like (I/O) and along with it is a 7.5 merc kicker that I got with the boat and have no history on, other than it looks like mid-80's and the prior owner did use it for trolling, but he was grounded due to medical problems and hadn't used either in several years. The problems with the kicker are as follows: 1) no water coming out of indicator when running and 2) it idles like a champ, but once I put any load on it it bogs down and stalls. It sounds like I'm looking at a minimum of a carb re-build/cleaning, impeller replacement, but this mechanic has really been taking too long and I'm getting upset. He hasn't touched the kicker simply because he's waiting on parts for the I/O, even though I told him I want to use the kicker on a row boat so I can at least get some fishing in before the end of the season :mad: Sorry for the long post, I'm just steamed - my questions are these: he said I'm more than welcome to come get one or both and do the work myself and I'm starting to lean that way on the outboard. I'm pretty good mechanically, but haven't really done much on the marine/outboard side of things. What is everyone's opinion as to whether I leave it with this guy, or get it back and do the work myself (after purchasing a manual). I just know that he's going to get the I/O parts in, then realize that he needs parts for the Merc., which will be another 2 weeks :mad: and although he fixes O/B's he isn't a dealer that stocks parts. There are a few around though, so I could get the parts myself. He's not a bad guy, just really swamped with winterizations - it's just frustrating cause I'm trying to get back out on the water this year. Any thoughts/advice would be greatly appreciated, especially any estimates on possible costs for me on the outboard side of the repair if I left it with him vs. doing the work myself. THANKS!
 

Wiggy

Petty Officer 2nd Class
Joined
Aug 16, 2005
Messages
130
Re: Merc 7.5 - advice...

To be honest a carb rebuild and water impeller should take no more than half a day with a manual. <br /><br />I'm a novice and with some advice on this forum and a manual, I've tackled all jobs so far.<br /><br />Have a go, you'll surprise yourself!
 

goinhungry

Seaman
Joined
Sep 8, 2005
Messages
71
Re: Merc 7.5 - advice...

Thanks. Anyone have any idea of a ball park cost the I'd be looking at taking it home and doing it myself vs leaving it with the mechanic? I guess it also might be worth it for me to do it, just so I can familarize myself with my motor...
 

dajohnson53

Lieutenant Commander
Joined
Apr 28, 2004
Messages
1,627
Re: Merc 7.5 - advice...

I'm going to assume that your 7.5 is fairly similar to my 9.8. <br /><br />I'm no mechanic. The only two mechanical things I've done for many, many years (other than change spark plugs and oil) is the impeller replacement and carb cleaning I did on my 9.8 recently. With a good manual (probably either a generic or factory will do - I have both and both are adequate for these two jobs), I'd say a "few hours" and $50 - $100 would be total, assuming no frozen, corroded or broken parts.<br /><br />Water pump: Probably 2-3 hours max (1 hour the second time!), $5-15 for parts. Sometimes you can buy a complete water pump rebuild kit. For some of the older kickers, you can only find the impeller, which is almost always OK anyway. Potential issues: difficulty removing lower unit and/or difficulty reassembling water pump (it can be frustrating getting the impeller on the shaft, but it just takes a few attempts). If you encounter either problem, post back here for a wealth of experience from BTDT folks.<br /><br />Carb clean and/or rebuild - again about 2- 3 hours total effort at the most (again, an hour the second time!). You can either go with a complete rebuild kit ($15 - $70, depending on the age of the engine; newer kits seem to be cheaper) or just a fuel pump rebuild kit ($8) and a carb gasket kit (another $8). I went with the latter, cheaper kits because the rebuild kit for my carb was pushing $70. It worked fine. You also need a gallon can of carb cleaner (to soak it in - $10, but reusable many times) as well as a can or two of spray carb cleaner and a source of compressed air (compresser or cans of compressed air). Using the service manual, it's pretty easy step by step - I didn't have a problem other than carelessness which caused me to break the plastic venturi in the carb (another $2).<br /><br />Just like you, I could have had the mechanic do it - the cost wasn't really a factor, but the time delay was. Also, like you, it was very good for me to familiarize myself with the engine, and I enjoyed the project.<br /><br />Editorial comment: I just HATE mechanics or any service people that aren't smart enough to double task on a job like this. I can't think of any excuse for not starting on your kicker while he's waiting for parts for the big engine. I'd look for another guy, although I know there are probably other factors involved. Good luck with your project.
 

goinhungry

Seaman
Joined
Sep 8, 2005
Messages
71
Re: Merc 7.5 - advice...

D. - Thanks so much for your imput and knowledge - it really helps a TON! I think I will go ahead and give it a shot myself. The mechanic seems to be a good guy (unfortunately he's the ONLY mechanic w/in 50 miles willing to touch a OMC Stringer, so I'm stuck with him on that...), but my dad was a mechanic, and he once said that "waiting for parts" is a typical excuse that garages who have overbooked or have poor planning use to get some more time... I'll let you know how it turns out - thanks again!!
 
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